Google results are dominated by the Expedia Group (a conglomerate of tons of different brands: https://www.expediagroup.com/home/default.aspx). While Google's practices have definitely hurt, it's a huge business, and probably a larger reason why a new flight search competitor can't get off the ground.
As a customer, it's annoying there isn't more diversity anymore. Generic travel searches are dominated by these brands, plus articles full of affiliate links that are hard to trust.